Ground-based and airborne radar systems are often used to detect objects in a specified area by using radio waves to determine the range, altitude, direction and speed of the objects. These radar systems can be used to detect aircrafts, automobiles, guided missiles, terrain or the like. In a transmission mode of operation, radar systems emit radio waves or microwaves, which are reflected from any objects within their path of travel. In a reception mode of operation, the radar systems detect the energy of the reflected waves for determining the range, altitude, direction and speed of targets. However, in environments cluttered with electromagnetic (EM) activity, distinguishing targets of genuine interest from electromagnetic clutter becomes difficult.
Nonlinear radar (NR) addresses some of these problems when monitoring RF activity in a particular area or application. For example, NR produces response frequencies from nonlinear targets (e.g., electronics or metal objects), that are different from those transmitted by linear radar, thereby allowing a way to distinguish natural clutter from the response of nonlinear targets. NR has also been used in military operations to detect concealed weapons, electronics and other man-made objects, in addition to device detection for FCC part 15 compliance.
NR is used in insect tracking, where insects are fitted with nonlinear tags and tracked to study movement and foraging behavior. However, NR still falls short in adapting to an increasingly cluttered EM environment, or other radar, communication and electronic systems which required interference-free operation.
Therefore there is a need in the art for implementing NR to adapt to and co-exist in the EM environment.